The present invention relates to a worktable that can be used to form a hole in a substrate. The substrate may be a flexible polyimide material that is subsequently assembled into a flexible circuit board of an electronic assembly.
Electronic assemblies may incorporate flexible circuit boards to provide an interconnect between integrated circuits and/or integrated circuit packages. The flexible circuit boards may contain patterned conductive material located on opposite surfaces of a flexible dielectric substrate. It may be desirable to create through holes/vias in the dielectric material to connect the conductive material on one side of the substrate to the conductive material on the other side of the substrate. a The vias are typically formed by initially creating holes in the substrate. The substrate is then placed in a plating bath to form the vias.
The holes can be created with a laser that scans a sheet of dielectric material mounted to a worktable. The dielectric material is typically secured to a surface of the worktable with tape. It is important to maintain the flatness of the dielectric material to insure the accuracy of the laser hole forming process.
Although the dielectric material is typically stretched onto the worktable, the tape has been found to be insufficient in maintaining the flatness of the material. Additionally, it is desirable to provide a worktable that has no backing material to insure proper operation of the laser. A backing material may cause an undesirable reflection of the laser beam and contamination of lased holes. It would therefore be desirable to provide a worktable that can provide sufficient tension to a dielectric material. It would also be desirable to provide a worktable that sufficiently tensions a dielectric material but does not have a backing surface.
One embodiment of the present invention is a worktable that can be used to support a substrate while forming a hole therein. The worktable may have an actuator that pulls the substrate.